Projector projecting password

ABSTRACT

A projector system of the present invention includes a projector  10  and a personal computer PC as an information terminal, which communicate with each other via a network connection. The projector  10  generates a password required for establishment of the network connection and projects the password on a screen SC. A user of the personal computer PC inputs the password projected on the screen SC. The password is used for authentication of the network connection between the projector  10  and the personal computer PC and cipher communication therebetween. This arrangement of the present invention enhances the convenience of the projector that is capable of establishing a network connection with the information terminal, while ensuring secrecy of communicating data.

This is a Continuation of application Ser. No. 10/228,334 filed Aug. 27,2002. The disclosure of the prior application is hereby incorporated byreference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a projector that projects a password.

2. Description of the Related Art

Data projectors have become popular to enlarge and project the contentsof an on-screen display of an information terminal, such as a personalcomputer. The projector may establish a network connection with theinformation terminal via cable communication or via wirelesscommunication. A password is generally required for establishment of thenetwork connection.

Cipher communication is adopted to assure security and prevent illegalconnection and interception of data in a projector that projects imagedata received from an information terminal connecting with the projectorvia wireless communication. For example, WEP (Wired Equivalent Privacy)technique is applied for cipher communication. In the WEP-based ciphercommunication, both a data transmitter side and a data receiver sideinput a common password. The common password is used for authenticationof the connection and for encoding and decoding of communicating data.

For size reduction and good portability, the projector is typically notprovided with a keyboard. A remote control or buttons on the projectorare accordingly used for input of required data into the projector.Input of a password into the projector is accordingly rather time- andlabor-consuming. In order to simplify a password input operation, oneapplicable technique causes the projector to generate a password. Thereis, however, difficulty in accurately notifying the user of theinformation terminal of the password. This problem is not restricted toinput of the password for cipher communication but is commonly found inthe case of requirement of a password for establishing communicationbetween the information terminal and the projector.

SUMMARY OF THE INVENTION

The object of the present invention is thus to enhance the convenienceof a projector that is capable of establishing a network connection withan information terminal while ensuring secrecy of communicating data.

In order to attain at least part of the above and the other relatedobjects, the present invention is directed to a projector that iscapable of establishing network connection with an information terminal,which supplies image data to be projected. The projector includes: apassword generation module that generates a password to be input intothe information terminal for establishment of the network connection;and a password projection module that projects the password.

The network connection of the projector of the present invention and aninformation terminal constructs a projector system. In the process ofestablishing the network connection between the projector and theinformation terminal, the projector carries out authentication with thepassword and identifies the legitimate connection. The informationterminal is generally provided with a keyboard, which facilitates inputof the password, compared with the projector.

The projector of the present invention may utilize a random digit togenerate the password. The password is input at the information terminalincluding the keyboard. This arrangement does not require manual inputof the password at the projector, thus enhancing the convenience of theprojector system. The generated password is projected and displayed on ascreen or the like. The user of the information terminal is thusaccurately informed of the password and can input the correct passwordinto the information terminal.

For the security, the password is generally not open to the public. Theprojector of the present invention is typically used in a limited spacelike a conference room. There is accordingly no fear of leaking thepassword to general public. This arrangement thus effectively preventsexternal illegal connections and ensures secrecy of communicating data.

In accordance with one preferable application of the invention, thenetwork connection represents a connection via wireless ciphercommunication, and the password generation module generates the passwordused for the wireless cipher communication. The projector further has acipher communication module that uses the password for the wirelesscipher communication with the information terminal.

Wireless communication, especially wireless cipher communication may beapplied for the network connection. This application of the inventiongenerates the password used for cipher communication (an encoding keyand a decoding key). A common password may be used in both of theprojector and the information terminal, or alternatively differentpasswords may be used. In the former case, another information terminallocated in the vicinity of the projector or the information terminalthat supplies data may also be involved in the network connection byrequired settings including the password to fetch data. In the lattercase, another information terminal is informed of only the encoding keyor a password for establishing the network connection and can thus notdecode the fetched data.

In the projector of the above application, it is preferable that thepassword generation module updates the password after establishment ofthe network connection to generate an updated password, and that thecipher communication module uses the updated password for the wirelesscipher communication with the information terminal.

The updated password may be generated periodically or for each packet inthe case of packet communication. This arrangement further heightens thesecrecy of communicating data.

In one preferable embodiment of the projector of the invention, thepassword generation module generates a random password at each time ofpower supply to the projector.

In this embodiment, the password is generated at random at each time ofpower supply. Since one password is not continually used, thisarrangement ensures secrecy of communicating data.

In accordance with another preferable application of the presentinvention, the projector further has a generation instruction modulethat is operated by a user to give an instruction for generating thepassword. The password generation module generates the password inresponse to the instruction.

In this application, the password is generated in response to intentionof a user of the projector. Namely the password is generated accordingto the requirement to ensure secrecy of communicating data.

In accordance with still another preferable application of theinvention, the projector further has a specification module that isoperated by a user to specify a projection form of the password.

The projection form includes the projected and displayed position of thepassword on the screen and the character size. The projection form maybe arbitrarily specified according to the area of the conference roomwhere the projector is installed, the size of the screen, and thesetting conditions.

In the projector of the present invention, it is preferable that thepassword projection module stops projection of the password when thenetwork connection is established.

In this arrangement, establishment of communication is confirmed byprojection or non-projection of the password. The projection of thepassword may be ceased after elapse of a preset time period as well asat the time of establishment of the network connection. This restrictsthe projection time of the password and thus heightens the secrecy ofthe password.

There are a diversity of applications of the present invention otherthan the projector described above. The possible applications include aprojection method, a computer program for actualizing the projectionmethod, a recording medium in which the computer program is recorded,and a data signal that includes the computer program and is embodied ina carrier wave. The variety of additional arrangements described abovemay be adopted in the respective applications.

The technique of the present invention may be actualized by a computerprogram or a recording medium in which the computer program is recorded.The computer program may be a whole program for driving the projector ora partial program for exerting the functions of the present invention.Typical examples of the recording medium include flexible disks,CD-ROMs, magneto-optic discs, IC cards, ROM cartridges, punched cards,prints with barcodes or other codes printed thereon, internal storagedevices (memories like a RAM and a ROM) and external storage devices ofthe computer, and a variety of other computer readable media.

These and other objects, features, aspects, and advantages of thepresent invention will become more apparent from the following detaileddescription of the preferred embodiments with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates the construction of a projector systemincluding a projector in a first embodiment of the present invention;

FIG. 2 is a flowchart showing a process of establishing a networkconnection between the projector and a personal computer PC; and

FIG. 3 is a flowchart showing a process of establishing a networkconnection between the projector and the personal computer PC in asecond embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Some modes of carrying out the present invention are described below aspreferred embodiments in the following sequence:

-   A. Construction of Projector System-   B. Network Connection-   C. Second Embodiment-   D. Modifications    A. Construction of Projector System

FIG. 1 schematically illustrates the construction of a projector systemincluding a projector 10 in a first embodiment of the present invention.The projector system of the embodiment includes the projector 10 and apersonal computer PC, which establish a network connection via wirelesscommunication. A plurality of personal computers may be connected to theprojector 10 in this projector system. Another information terminal mayreplace the personal computer PC. The projector system is utilized in alimited space, such as a conference room or an auditorium.

The projector 10 is a data projector that projects data received fromthe personal computer PC on a screen SC. The projector 10 and thepersonal computer PC make cipher communication. In the arrangement ofthis embodiment, an identical password is set in both the projector 10and the personal computer PC. This password is used for authenticationof a network connection, encoding, and decoding.

The projector 10 includes a power switch 12, a password generationmodule 20, a password generation instruction module 22, a displaycontrol module 30, a display specification module 32, a projectionmodule 40, and a cipher communication module 50. The projector 10 alsohas a storage module 34 to store setting information for a networkconnection, such as a protocol and an address.

The password generation module 20 generates a password, which iscommonly used in the cipher communication module 50 of the projector 10and a cipher communication unit 100 of the personal computer PC, inresponse to an ON operation of the power switch 12. The technique ofthis embodiment uses a random digit for generation of the password. Thepassword is accordingly generated at random at every time of powersupply to the projector 10. The password generation module 20 isconnected to the password generation instruction module 22 and maygenerate the password in response to a user's instruction. The passwordgeneration instruction module 22 gives an instruction of generating thepassword to the password generation module 20 in response to the user'soperation. This arrangement effectively prevents illegal connection tothe network and interception of communication data.

The display control module 30 makes the data input from the personalcomputer PC via the cipher communication module 50 subjected to adiversity of image processing and generates an image, which is to beprojected by the projection module 40. As illustrated, the passwordgenerated by the password generation module 20 and the settinginformation for the network connection may also be projected on thescreen SC. The display specification module 32 is connected to thedisplay control module 30 to arbitrarily specify the display position ofthe password on the screen SC and the character size in response to theuser's operation, for easy view of the projected password.

The projection module 40 includes a light source and a projectionoptical system (not shown) and projects the image generated by thedisplay control module 30 and the password on the screen SC.

The cipher communication module 50 utilizes the password generated bythe password generation module 20 for authentication of a networkconnection. The cipher communication module 50 also decodes encoded datasent from the personal computer PC and supplies the decoded data to thedisplay control module 30.

The personal computer PC includes a cipher communication unit 100, anapplication software program 110, and an input unit 120. The user of thepersonal computer PC inputs the password projected on the screen SC andsetting information for the network connection through operations of akeyboard and a mouse (not shown). The cipher communication unit 100utilizes the input password to establish the network connection with theprojector 10, encodes image data of the application software program 110with the password, and transmits the encoded image data to the projector10.

B. Network Connection

FIG. 2 is a flowchart showing a process of establishing a networkconnection between the projector 10 and the personal computer PC. Theleft flow shows a series of processing at the projector 10, whereas theright flow shows a series of processing at the personal computer PC. Theprojector 10 generates a password (step S100). The password is generatedin response to power supply (that is, an ON operation of the powerswitch 12) or by an operation of the password generation instructionmodule 22. The projector 10 projects and displays the generated passwordon the screen SC (step S110). The setting information for the networkconnection may be projected together with the password. The user of thepersonal computer PC inputs the password projected on the screen SCthrough an operation of the keyboard (step S120). In order to establishcommunication with the projector 10, the user requires authentication ofthe network connection with the input password (step S130). Theprojector 10 authenticates the input password in response to arequirement of authentication from the personal computer PC. Whenconnection is established with the personal computer PC (step S140), theprojector 10 stops the projection and display of the password on thescreen SC (step S150). Establishment of communication is confirmed bythe ceased projection of the password. Projection of the password may beceased after a predetermined time has passed since start of theprojection. This arrangement heightens the secrecy of the password.Establishment of the network connection allows cipher communicationbetween the projector 10 and the personal computer PC.

In the projector 10 of the first embodiment, the password generationmodule 20 generates a password. The user of the projector 10 isaccordingly not required to input the password into the projector 10.This arrangement enhances the convenience of the projector system. Thegenerated password is projected on the screen SC, so that the user ofthe personal computer PC is accurately informed of the password to beinput into the personal computer PC.

For the security, the password is generally not open to the public. Theprojector 10 of the embodiment is used in a limited space like aconference room. There is accordingly no fear of leaking the password togeneral public. The arrangement of the embodiment thus effectivelyprevents external illegal connections and ensures secrecy ofcommunicating data.

In the arrangement of this embodiment, a common password is used in boththe projector 10 and the personal computer PC. Another nearbyinformation terminal can receive data from the personal computer PCafter establishing a similar network connection with the personalcomputer PC.

C. Second Embodiment

FIG. 3 is a flowchart showing a process of establishing a networkconnection between the projector 10 and the personal computer PC in asecond embodiment of the present invention. The processing of steps S100through S150 is identical with that of the first embodiment, and theconstruction of the projector system is also identical with that of thefirst embodiment. In the arrangement of the second embodiment, afterestablishment of communication between the projector 10 and the personalcomputer PC, the projector 10 newly generates a password (step S160).Generation of the new password may be executed automatically afterestablishment of communication or in response to the user's operation ofthe password generation instruction module 22. Since the communicationhas already been established between the projector 10 and the personalcomputer PC, the newly generated password is not projected on the screenSC but is transmitted to the personal computer PC. The personal computerPC receives the transmitted password and updates the password (stepS170). Generation of the new password and updating may be carried outperiodically or for each transmitted packet. The projector 10 and thepersonal computer PC make cipher communication with the updatedpassword.

The technique of the second embodiment does not project the newlygenerated password on the screen SC. This arrangement prevents any thirdperson from being informed of the updated password, thus ensuring highsecrecy of communicating data.

D. Modifications

The above embodiments and their modifications are to be considered inall aspects as illustrative and not restrictive. There may be manymodifications, changes, and alterations without departing from the scopeor spirit of the main characteristics of the present invention. Allchanges within the meaning and range of equivalency of the claims aretherefore intended to be embraced therein.

D1. Modified Example 1

The above embodiment uses a common password for both coding and encodingof data in cipher communication. Different passwords may alternativelybe used for coding and encoding of data, respectively. In the lattercase, the password generation module 20 of the projector 10 generates apassword corresponding to an encoding key used in the personal computerPC and another password corresponding to a decoding key used in theprojector 10. The password corresponding to the encoding key isprojected on the screen SC. The user inputs the projected password intothe personal computer PC.

This arrangement informs only the projector 10 of the password fordecoding the data encoded by the personal computer PC, thus effectivelypreventing interception of data by any other device.

D2. Modified Example 2

The above embodiment regards wireless cipher communication between theprojector 10 and the personal computer PC. The technique of the presentinvention is also applicable for cable communication.

D3. Modified Example 3

The above embodiment regards the image display system including theprojector (projector system). The technique of the present invention isalso applicable to other image display systems where an image displaydevice and an information terminal establish a network connection.

The scope and spirit of the present invention are indicated by theappended claims, rather than by the foregoing description.

1. A projector that is capable of establishing network connection withan information terminal, said projector comprising: a passwordgeneration module that generates a password to be input into saidinformation terminal for establishment of the network connection; and aprojection module that projects the password, and projects an imageaccording to image data supplied from said information terminal afterestablishment of the network connection.
 2. A projector in accordancewith claim 1, wherein the network connection represents a connection viawireless cipher communication, and said password generation modulegenerates the password used for the wireless cipher communication, saidprojector further comprising: a cipher communication module that usesthe password for the wireless cipher communication with said informationterminal.
 3. A projector in accordance with claim 2, wherein saidpassword generation module updates the password after establishment ofthe network connection to generate an updated password, and said ciphercommunication module uses the updated password for the wireless ciphercommunication with said information terminal.
 4. A projector inaccordance with claim 1, wherein said password generation modulegenerates a random password at each time of power supply to saidprojector.
 5. A projector in accordance with claim 1, said projectorfurther comprising: a generation instruction module that is operated bya user to give an instruction for generating the password, wherein saidpassword generation module generates the password in response to theinstruction.
 6. A projector in accordance with claim 1, said projectorfurther comprising: a specification module that is operated by a user tospecify a projection form of the password.
 7. A projector in accordancewith claim 1, wherein said projection module stops projection of thepassword when the network connection is established.
 8. A methodimplemented by a projector, said projector being capable of establishingnetwork connection with an information terminal and including aprojection module, said method comprising the steps of: (a) generating apassword to be input into said information terminal for establishment ofthe network connection; (b) projecting the password using the projectionmodule; and (c) projecting an image according to image data suppliedfrom said information terminal after establishment of the networkconnection, using the projection module.
 9. A computer readablerecording medium in which a computer program used for driving aprojector is recorded, said projector being capable of establishingnetwork connection with an information terminal and including aprojection module, said computer program causing a computer to attainthe functions of: generating a password to be input into saidinformation terminal for establishment of the network connection;projecting the password using the projection module; and projecting animage according to image data supplied from said information terminalafter establishment of the network connection, using the projectionmodule.